There really is a site for everything -- in this case two. Seatexpert.com and SeatGuru.com have super detailed reports of the ins and outs of each seat on each type of aircraft flown by the major airlines. Who knew that not all first class seats were created equal? Want to know which seats suffer from toilet flushing noise?
SeatGuru has a more comprehensive list of American carriers, but both are sites are useful. Enjoy!